Prophylaxis in chess refers to the strategic use of moves by a player to forestall their opponent’s potential actions. These moves, commonly known as prophylactic moves, are not only intended to enhance one’s own position, but also to limit the opponent’s ability to enhance theirs.
Numerous conventional and prevalent opening moves can be regarded as prophylactic in nature. One popular prophylactic concept is the advancement of the rook pawn adjacent to the king that has been castled, which can be executed to create breathing room for the king, thwart a pin, or avoid a piece advance (usually a knight).
We could have observed a prophylaxis of the mentioned type in our previous article From Russia With Love. Black played 8. … h6 as a precaution, as White threatened to attack the black king’s fortress soon, so the move would counter any possible charge to g5:
The Keres Variation of the Ruy López opening is a good example of a prophylaxis in the opening phase. White prepares the central advance of the d-pawn, but to prevent an awkward pin by a bishop from g4, they play h3 first:
And, of course, the Sicilian Defense enthusiasts are well-aware of this strategic move in the Najdorf Variation to counter the expected knight charge to b5:
However, it is crucial to recognize situations where such a move would be too preliminary, and actually lead to a tempo loss instead. Have a look at the following game, especially the move 7:
In positional play, prophylaxis serves as a distinguishing characteristic that aids in preventing opponents from venturing into hazardous, high-risk strategies while also penalizing those who play overly aggressively. The ability to employ prophylactic moves is a critical skill at more advanced levels of chess. Numerous renowned players, including Aron Nimzowitsch, Tigran Petrosian, and Anatoly Karpov, are known for their adeptness in prophylactic play, and even tactical players like Mikhail Tal and Garry Kasparov incorporate prophylaxis into their game.